My initial underground farm plot is 3*3, but I place and underground seed stockpile there, as well as the brewery, a farmer's workshop for thread production, 3 looms, and 3 clothiers in the area, plus the QS' needed to feed these, although I don't build all of these at once. I tend to use the area as a temporary stockpile out of reach of thieving critters early on, though, and since it's dug in dirt it's fairly quick to dig (although my miners are always completely untrained on embark).
After that I dig the workshop area, which typically ends up being dug in stone underneath the farming area and get to work constructing cage traps, mine carts, mechanisms, etc. and that's when the courtyard builders/stockpile haulers see a drain in manpower.
Next comes the kitchen/animal pen/butcher/tanner/fish cleanery, although I tend to dig out only the animal pen at first to get the animals in place.
Thereafter the initial dining hall, and I also tend to dig a 3*3 room for the accountant. That's about when the summer migrants arrive, and I still don't have any bed rooms.
Now, if I was to embark in an environment that's too hostile on the surface, like a glacier, I'd probably skip bringing grazing livestock and try to buy them from caravans instead. The only thing I want from grazers is wool, anyway (I could go one step further and buy wool cloth directly, to support moods), but as far as I know there aren't any shearable cavern critters except trolls, which are considered too intelligent to be kept in captivity by dorfs, and so are better off killed (I've gotten some thread from clown hair, but that thread is not usable for cloth, and I suspect the same thing goes for wooly titans/FBs).
I also SHOULD get complications in the form of an aquifer since I try to have them in my embarks, although so far I haven't been completely blocked by them.